1. Field of the Invention
This invention relates generally to furniture drawer slide assemblies and, more specifically, to an improved drawer glide that can be used with a variety of lengths of drawer slides, thereby reducing the number of different lengths of In drawer slides required for use with drawers of various lengths, and which ensures better securement between the drawer glide and the drawer slide.
2. Description of the Prior Art
In order to improve the ease of sliding of wood drawers, many furniture manufacturers have adopted the use of metal drawer slide assemblies, which utilize an elongated stationary lower metal drawer guide, also known as a case guide, secured to the inside structure of the furniture article, an elongated upper metal drawer slide secured to the bottom of a drawer at the front and rear ends of the drawer, and a plastic drawer glide mounted to the rear wall of a drawer to facilitate movement of the drawer along the lower metal drawer guide. In most conventional drawer slide assemblies, the lower metal drawer guide consists of a generally U-shaped (or T-shaped) metal rail in cross-section, having flanges projecting horizontally outwardly from the upper ends thereof. Each of these horizontally projecting flanges is typically folded over along its length, so that the effective thickness of each horizontal flange is twice the thickness of the metal used to fabricate the metal rail. The upper metal drawer slide found in the prior art, is generally C-shaped in cross-section and has an integral, upwardly-extending metal tab member at the rear end thereof that is secured to the rear wall of the drawer. A typical arrangement of such conventional drawer slide assemblies is shown in co-owned U.S. Pat. Nos. Re. 32,134 and 4,501,452.
A plastic stop member, referred to by many in the art as a case glide, is also provided at or near the front end of the elongated lower metal drawer guide that serves to prevent the drawer from being prematurely or inadvertently pulled out of the associated furniture unit. The plastic drawer glide is provided with a pair of opposing ways: or runners that provide plastic-to-metal, as opposed to metal-to-metal, bearing surface to facilitate movement of the drawer along the elongated lower drawer guide. The opposing ways receive and ride along the outwardly projecting horizontal flanges of the drawer guide. A gap in the drawer glide just above the opposing ways can desirably barely accommodate the horizontal projections of the plastic stop member with no interference, so that the drawer can be inserted in the furniture unit with the stop and the drawer glide already installed. This gap also allows the drawer to be removed from the furniture unit, but only upon the use of sufficient force to squeeze the horizontal projections of the stop member into the gap of the drawer glide. Thus, the stop provides a warning to a user that the drawer is about to be pulled out of the furniture unit, and application of additional force will cause the drawer glide to pass beyond the stop.
A major shortcoming of the conventional drawer slide assembly is the need to provide drawer length-specific sizes of drawer slides. One reason that drawer length-specific sizes of drawer slides are required is that the upwardly-extending tab member at the rear end of the drawer slide provides the primary means for securing the rear end of the drawer slide to the bottom of the drawer. As a result, the drawer slide could not have a length that would cause the tab member to extend past the rear wall of the drawer.
The drawer glide of many conventional drawer slide assemblies is a plastic part that utilizes an elongated integral plastic male extension that is received inside the rear end of the C-shaped drawer slide. The plastic extension of the drawer glide is inserted into the rear end of the C-shaped drawer slide until a front face of the drawer glide lies flush against the upwardly-extending tab member at the rear end of the drawer slide. Screws or other suitable fasteners are used to secure both the drawer glide and the upwardly-extending tab member to the rear wall of the drawer. While the plastic extension of the drawer glide may provide some incidental support to the drawer slide, the primary purpose of the plastic extension is to provide a plastic bearing surface to facilitate movement of the drawer along the drawer guide.
By only being able to match a specific length of drawer slide with a given drawer length, a large array of drawer slides having various lengths must be manufactured to meet the demands of the furniture industry. This increases the number of stock-keeping units (xe2x80x9cSKU""sxe2x80x9d) that must be provided by the supplier of drawer slide assemblies.
The upwardly-extending tab portion at the rear of the drawer slide also requires additional working of the metal during manufacture of the drawer slide, which adds to production time and cost. Similarly, there are disadvantages of conventional metal drawer slides due to the cost of complicated tooling for stamping manufacturing processes, or alternatively, where the metal drawer slides are roll formed, not only is complicated tooling required, but also, production time is detrimentally slowed down. The present invention overcomes these shortcomings by eliminating the upwardly-extending tab portion of the metal drawer slide and changing the manner in which the drawer glide couples with the rear end of the drawer slide and the rear wall of the drawer.
It is an object of the present invention to provide a drawer slide assembly that can be used on a variety of lengths of drawers, so as to significantly reduce the number of SKU""s, or different lengths of drawer slides, required to meet the demands of the furniture industry. Instead of having a drawer slide that terminates at an upwardly-extending tab member at the rear end of the metal drawer slide, the present invention requires the drawer slide to extend past the rear wall of the drawer.
This object of the present invention is achieved by means of an improved drawer glide., wherein instead of a male plastic forwardly-projecting extension of the drawer glide, the drawer glide is provided with a female recess in its front face. The metal drawer slide projects rearwardly beyond the rear wall of the drawer and is received in the female recess of the drawer glide. In a first embodiment of the improved drawer glide, the female recess is present instead of the male plastic extension. The female recess is of sufficient depth to accommodate a length of a drawer slide that extends as much as xc2xc inch beyond the rear wall of the drawer. According to this embodiment, the drawer slides can thus be provided with a manufacturing tolerance of {fraction (1/16)}xe2x80x3, as opposed to needing more exact drawer-length specific drawer slides.
In a most preferred embodiment, the recess of the plastic drawer glide is elongated, having sufficient depth to accommodate a length of drawer slide that extends as much as xc2xd inch beyond the rear wall of the drawer, whereby a greater variety of lengths of drawers can be used with a given drawer slide. The drawer slides can vary in xc2xcxe2x80x3 increments, resulting in fewer drawer slide SKU""s than the first embodiment of the present invention.
A need exists to reinforce the walls of the female recess and a wall member forming the main vertical body portion of the plastic drawer glide. This need arises from the fact that a rear-most portion of the drawer slide is received within the female recess of the drawer glide, and the drawer slide transfers internal stresses, direct forces, and torque, for example from the weight of the drawer and the weight of the contents of the drawer, to the drawer glide. The drawer slide receiving area of the female recess also may be slightly smaller than the cross-sectional dimension of the rear-most portion of the drawer slide, so the drawer slide may have a tendency to bias opposing ways of the drawer glide away from one another, tending to weaken or crack the drawer glide. Reinforcement of the drawer glide is therefore desirable to compensate for these factors. One form of such reinforcement is the use of a metal insert plate imbedded within the plastic drawer glide. The metal insert plate provides internal rigidity and strength to the drawer glide.
Another form of reinforcement, which has several benefits from a manufacturing standpoint, is the use of integral flanges or gussets between the outer walls defining the female recess and the wall member forming the main vertical body portion of the drawer glide. These integral flanges or gussets are preferably wedge-shaped, i.e. pie-shaped, and are spaced along the sidewalls and top wall forming the female recess of the drawer glide.
Another improvement incorporated into the drawer glide of the present invention is a locking mechanism to ensure securement of the rear-most end of the drawer slide within the female recess of the drawer glide. This locking mechanism preferably takes the form of a ramped locking tab extending downwardly from the upper wall of the female recess of the drawer glide. A complementary aperture spaced inwardly from the extreme rear end of the drawer slide receives the locking tab once the drawer slide has been inserted a sufficient distance into the drawer glide.
Advantageously, this locking mechanism allows for easy preassembly of the drawer slide and drawer glide prior to attachment to a drawer, which assists in obtaining proper perpendicular alignment of the drawer slide relative to the rear wall of the drawer once the drawer slide and drawer glide are attached to the drawer. By extending from the upper wall of the female recess of the drawer glide, the integral plastic locking tab also beneficially avoids the need for any metal back bent tabs along the length of the drawer slide, which allows for less difficult and less expensive roll-forming or stamping of the drawer slide.
The drawer glide also has opposing ways that extend forwardly of the main wall member of the drawer glide, resulting in a longer gliding surface, i.e. a longer region of sliding contact between the opposing ways of the drawer glide and the metal drawer slide.